Document receiving devices known as “stackers” are used in the field of mail processing, for example, and in particular receive full envelopes from a machine for inserting documents into envelopes.
As is known in the art, envelopes coming from a machine for inserting documents into envelopes drop into a hopper in which, given the stream of envelopes leaving the machine, they are piled up higgledy-piggledy.
Accordingly, when the hopper is full and/or the machine for inserting documents into envelopes has ceased to function, human intervention is required to return the envelopes to the correct order and stack them to facilitate subsequent operations (routing, distribution, etc.).
It will be noted that the problems referred to above are not specific to envelopes and may relate to any type of document arriving in a common receiving device where they are liable to become mixed up.
It would therefore be useful to have a document receiving device preventing the mixing of documents.